The present invention relates, in general, to resistors used to isolate electrical signals, and more particularly, to a novel type of isolation resistor used to isolate signals at the terminals of semiconductor components.
Previous methods for isolating signals of semiconductor components involved connecting individual isolation resistors in series with the terminals of the semiconductor components. This isolated the signal on the terminal from signals on other terminals and on other semiconductor components. This method of providing isolation was generally used in the industry to prevent the failure of a signal on one terminal of a component from affecting the operation of the other components. Usually the semiconductor components were mounted on a printed circuit board along with the individual isolation resistors. The printed circuit cards on which the resistors were mounted generally were customized for a particular circuit function in a particular package configuration and were not sufficiently flexible to accommodate a variety of package types or component types. Although individual isolation resistors were generally used in the industry, a specific application was for isolating signals on boards used to burn-in semiconductor components. In this application, boards usually had sockets for mounting the semiconductor components during the test or burn-in procedure. After repeated uses, these sockets became worn and had to be replaced. Generally, the replacement procedure damaged the printed circuit board assembly and limited the useful life of the assembly.
Accordingly, it would be desirable to have a flexible method to electrically isolate semiconductor components which accommodates various package types and component types, and which extends the life of the assemblies in which these components are used.